This application requests continued support for the Vanderbilt Infection Pathogenesis and Epidemiology Research (VIPER) Training Program. The objective is to prepare postdoctoral fellows for careers as investigators in infectious diseases. Training is in basic laboratory research to study disease pathogenesis using molecular and cellular methods, as well as in patient-oriented epidemiology and outcomes research. There is broad expertise among our program faculty covering immunology and inflammation, virology (HIV and Other Viruses), bacteriology, personalized medicine, vaccines, and epidemiology and outcomes research (HIV, TB, hospital epidemiology, and global health). Participating faculty are mainly in the Infectious Disease Divisions of Medicine and Pediatrics and the Department of Pathology, Microbiology and Immunology. This program has a strong track record of interactive training of post-MD fellows from both Medicine and Pediatrics, and also includes PhD trainees. There is extensive collaboration among mentors. Long-term success is maximized by a customized research career plan for each trainee with a dedicated mentor, and under the supervision of an expert advisory committee and the Program Director. A course in responsible conduct of research is required. Physicians complete a clinical year of clinical training before starting VIPER training, and a minimum of two years of research training is required for all fellows.